This invention relates to a V-belt type transmission apparatus used for a variable-speed type transmission for a vehicle or the like, and is more particularly directed to a V-belt transmission apparatus having an endless metallic belt with a large number of V-shaped metallic engaging members. Each V-shaped metallic member has an outwardly directed engaging surface which contacts the metallic belt, such that the metallic members are disposed in a line in the lengthwise direction of the metallic belt to form a V-belt assembly. The V-belt assembly is applied between a pair of V-pulleys on a driving side and a driven side for effecting a power transmission therebetween.
In V-belt transmissions previously proposed by the applicant herein, a large number of intermediate members such as hollow rollers or the like are interposed between adjacent members inside the metallic belt and each of the metallic members is held so as to be slidably moved outwards and inwards so that if the metallic members are pushed into the V-groove of the V-pulley, then outwardly directed reaction forces are generated in response to the pushing-in operation. The intermediate members are thereby brought into pressure contact, at their outwardly directed engaging surfaces, with the metallic belt, resulting in their firm engagement therewith, and thereby the metallic belt is applied with the tension force generated by the V-pulley for effecting power transmission. This type of apparatus, however, has the disadvantage that there is a large stress generated in the metallic belt where it engages each of the metallic members. This stress results from the foregoing reaction force. It is desirable for improving durability thereof, that the reaction forces be distributively applied to the metallic belt not only through the respective metallic members but also through the respective intermediate members.